This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have expressed and purified mutants of Pseudomonas aeruginosa azurins which possess reduction potentials and EPR spectra akin to type 1 (T1) or ?blue copper? sites despite lack of thiolate ligation. To date research has indicated the necessity of thiolates for T1 coordination. In concert with ongoing electronic absorption, EPR, and electron transfer kinetics studies, we wish to use XAS and EXAFS analysis to elucidate the origin of our peculiar EPR spectra as well as to assess site reorganization during oxidation/reduction processes.